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Mendonça-Dos-Santos M, Gonçalves TCT, Falconi-Sobrinho LL, Dos Anjos-Garcia T, Matias I, de Oliveira RC, Dos Santos Sampaio MDF, Dos Santos Cardoso F, Dos Santos WF, Machado HR, Coimbra NC. GABAergic and glutamatergic inputs to the medulla oblongata and locus coeruleus noradrenergic pathways are critical for seizures and postictal antinociception neuromodulation. Sci Rep 2024; 14:4069. [PMID: 38374419 PMCID: PMC10876930 DOI: 10.1038/s41598-024-53744-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2023] [Accepted: 02/04/2024] [Indexed: 02/21/2024] Open
Abstract
We investigated the participation of the nucleus of the tractus solitarius (NTS) in tonic‒clonic seizures and postictal antinociception control mediated by NMDA receptors, the role of NTS GABAergic interneurons and noradrenergic pathways from the locus coeruleus (LC) in these phenomena. The NTS-lateral nucleus reticularis paragigantocellularis (lPGi)-LC pathway was studied by evaluating neural tract tracer deposits in the lPGi. NMDA and GABAergic receptors agonists and antagonists were microinjected into the NTS, followed by pharmacologically induced seizures. The effects of LC neurotoxic lesions caused by DSP-4, followed by NTS-NMDA receptor activation, on both tonic‒clonic seizures and postictal antinociception were also investigated. The NTS is connected to lPGi neurons that send outputs to the LC. Glutamatergic vesicles were found on dendrites and perikarya of GABAergic interneurons in the NTS. Both tonic‒clonic seizures and postictal antinociception are partially dependent on glutamatergic-mediated neurotransmission in the NTS of seizing rats in addition to the integrity of the noradrenergic system since NMDA receptor blockade in the NTS and intrathecal administration of DSP-4 decrease the postictal antinociception. The GABAA receptor activation in the NTS decreases both seizure severity and postictal antinociception. These findings suggest that glutamatergic inputs to NTS-GABAergic interneurons, in addition to ascending and descending noradrenergic pathways from the LC, are critical for the control of both seizures and postictal antinociception.
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Affiliation(s)
- Marcelo Mendonça-Dos-Santos
- Laboratory of Neuroanatomy and Neuropsychobiology, Department of Pharmacology, Ribeirão Preto Medical School of the University of São Paulo (FMRP-USP), Av. Bandeirantes, 3900, Ribeirão Preto, São Paulo, 14049-900, Brazil
- Laboratory of Paediatric Neurosurgery and Developmental Neuropathology, Department of Surgery and Anatomy, Ribeirão Preto Medical School of the University of São Paulo, Av. Bandeirantes, 3900, Ribeirão Preto, São Paulo, 14049-900, Brazil
| | - Thaís Cristina Teixeira Gonçalves
- Laboratory of Neuroanatomy and Neuropsychobiology, Department of Pharmacology, Ribeirão Preto Medical School of the University of São Paulo (FMRP-USP), Av. Bandeirantes, 3900, Ribeirão Preto, São Paulo, 14049-900, Brazil
- Laboratory of Paediatric Neurosurgery and Developmental Neuropathology, Department of Surgery and Anatomy, Ribeirão Preto Medical School of the University of São Paulo, Av. Bandeirantes, 3900, Ribeirão Preto, São Paulo, 14049-900, Brazil
| | - Luiz Luciano Falconi-Sobrinho
- Laboratory of Neuroanatomy and Neuropsychobiology, Department of Pharmacology, Ribeirão Preto Medical School of the University of São Paulo (FMRP-USP), Av. Bandeirantes, 3900, Ribeirão Preto, São Paulo, 14049-900, Brazil
| | - Tayllon Dos Anjos-Garcia
- Laboratory of Neuroanatomy and Neuropsychobiology, Department of Pharmacology, Ribeirão Preto Medical School of the University of São Paulo (FMRP-USP), Av. Bandeirantes, 3900, Ribeirão Preto, São Paulo, 14049-900, Brazil
| | - Ivair Matias
- Laboratory of Neuroanatomy and Neuropsychobiology, Department of Pharmacology, Ribeirão Preto Medical School of the University of São Paulo (FMRP-USP), Av. Bandeirantes, 3900, Ribeirão Preto, São Paulo, 14049-900, Brazil
- Laboratory of Paediatric Neurosurgery and Developmental Neuropathology, Department of Surgery and Anatomy, Ribeirão Preto Medical School of the University of São Paulo, Av. Bandeirantes, 3900, Ribeirão Preto, São Paulo, 14049-900, Brazil
| | - Rithiele Cristina de Oliveira
- Laboratory of Neuroanatomy and Neuropsychobiology, Department of Pharmacology, Ribeirão Preto Medical School of the University of São Paulo (FMRP-USP), Av. Bandeirantes, 3900, Ribeirão Preto, São Paulo, 14049-900, Brazil
| | - Maria de Fátima Dos Santos Sampaio
- Laboratory of Neuroanatomy and Neuropsychobiology, Department of Pharmacology, Ribeirão Preto Medical School of the University of São Paulo (FMRP-USP), Av. Bandeirantes, 3900, Ribeirão Preto, São Paulo, 14049-900, Brazil
- Laboratory of Tissue and Cellular Biology, Centre of Biosciences and Biotechnology of Darcy Ribeiro Northern, Fluminense State University (UENF), Av. Alberto Lamego, 2000, Campos dos Goytacazes, Rio de Janeiro, 28013-602, Brazil
| | - Fabrízio Dos Santos Cardoso
- Laboratory of Neuroanatomy and Neuropsychobiology, Department of Pharmacology, Ribeirão Preto Medical School of the University of São Paulo (FMRP-USP), Av. Bandeirantes, 3900, Ribeirão Preto, São Paulo, 14049-900, Brazil
| | - Wagner Ferreira Dos Santos
- Neurobiology and Venoms Laboratory, Department of Biology, Ribeirão Preto School of Philosophy, Sciences and Literature of the University of São Paulo (FFCLRP-USP), Ribeirão Preto, SP, 14040-901, Brazil
| | - Helio Rubens Machado
- Laboratory of Paediatric Neurosurgery and Developmental Neuropathology, Department of Surgery and Anatomy, Ribeirão Preto Medical School of the University of São Paulo, Av. Bandeirantes, 3900, Ribeirão Preto, São Paulo, 14049-900, Brazil.
- Department of Surgery and Anatomy, Multiuser Centre of Neuroelectrophysiology, Ribeirão Preto Medical School of the University of São Paulo (FMRP-USP), Av. Bandeirantes, 3900, Ribeirão Preto, São Paulo, 14049-900, Brazil.
| | - Norberto Cysne Coimbra
- Laboratory of Neuroanatomy and Neuropsychobiology, Department of Pharmacology, Ribeirão Preto Medical School of the University of São Paulo (FMRP-USP), Av. Bandeirantes, 3900, Ribeirão Preto, São Paulo, 14049-900, Brazil.
- Department of Surgery and Anatomy, Multiuser Centre of Neuroelectrophysiology, Ribeirão Preto Medical School of the University of São Paulo (FMRP-USP), Av. Bandeirantes, 3900, Ribeirão Preto, São Paulo, 14049-900, Brazil.
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Biagioni F, Celli R, Puglisi-Allegra S, Nicoletti F, Giorgi FS, Fornai F. Noradrenaline and Seizures: A Perspective on the Role of Adrenergic Receptors in Limbic Seizures. Curr Neuropharmacol 2023; 21:2233-2236. [PMID: 35339181 PMCID: PMC10556380 DOI: 10.2174/1570159x20666220327213615] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2022] [Revised: 03/16/2022] [Accepted: 03/22/2022] [Indexed: 11/22/2022] Open
Abstract
BACKGROUND Noradrenergic fibers originating from the locus coeruleus densely innervate limbic structures, including the piriform cortex, which is the limbic structure with the lowest seizure threshold. Noradrenaline (NA) modulates limbic seizures while stimulating autophagy through β2- adrenergic receptors (AR). Since autophagy is related to seizure threshold, this perspective questions whether modulating β2-AR focally within the anterior piriform cortex affects limbic seizures. OBJECTIVE In this perspective, we analyzed a potential role for β2-AR as an anticonvulsant target within the anterior piriform cortex, area tempestas (AT). METHODS We developed this perspective based on current literature on the role of NA in limbic seizures and autophagy. The perspective is also grounded on preliminary data obtained by microinfusing within AT either a β2-AR agonist (salbutamol) or a β2-AR antagonist (butoxamine) 5 minutes before bicuculline. RESULTS β2-AR stimulation fully prevents limbic seizures induced by bicuculline micro-infusion in AT. Conversely, antagonism at β2-AR worsens bicuculline-induced seizure severity and prolongs seizure duration, leading to self-sustaining status epilepticus. These data indicate a specific role for β2-AR as an anticonvulsant in AT. CONCLUSION NA counteracts limbic seizures. This relies on various receptors in different brain areas. The anterior piriform cortex plays a key role in patients affected by limbic epilepsy. The anticonvulsant effects of NA through β2-AR may be related to the stimulation of the autophagy pathway. Recent literature and present data draw a perspective where β2-AR stimulation while stimulating autophagy mitigates limbic seizures, focally within AT. The mechanism linking β2-AR to autophagy and seizure modulation should be extensively investigated.
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Affiliation(s)
| | | | | | - Ferdinando Nicoletti
- I.R.C.C.S. Neuromed, Pozzilli, Italy
- Department of Physiology and Pharmacology, University Sapienza, Rome, Italy
| | - Filippo Sean Giorgi
- Human Anatomy, Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, Pisa, Italy
| | - Francesco Fornai
- I.R.C.C.S. Neuromed, Pozzilli, Italy
- Human Anatomy, Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, Pisa, Italy
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Biagioni F, Celli R, Giorgi FS, Nicoletti F, Fornai F. Perspective on mTOR-dependent Protection in Status Epilepticus. Curr Neuropharmacol 2022; 20:1006-1010. [PMID: 34636300 PMCID: PMC9886823 DOI: 10.2174/1570159x19666211005152618] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Revised: 09/15/2021] [Accepted: 09/22/2021] [Indexed: 11/22/2022] Open
Abstract
BACKGROUND The piriform cortex, known as area tempestas, has a high propensity to trigger limbic epileptic seizures. Recent studies on human patients indicate that a resection containing the piriform cortex produces a marked improvement in patients suffering from intractable limbic seizures. This calls for looking back at the pharmacological and anatomical data on area tempestas. Within the piriform cortex, status epilepticus can be induced by impairing the desensitization of AMPA receptors. The mechanistic target of rapamycin complex1 (mTORC1) is a promising candidate. OBJECTIVE The present perspective aims to link the novel role of the piriform cortex with recent evidence on the modulation of AMPA receptors under the influence of mTORC1. This is based on recent evidence and preliminary data, leading to the formulation of interaction between mTORC1 and AMPA receptors to mitigate the onset of long-lasting, self-sustaining, neurotoxic status epilepticus. METHODS The perspective grounds its method on recent literature along with the actual experimental procedure to elicit status epilepticus from the piriform cortex and the method to administer the mTORC1 inhibitor rapamycin to mitigate seizure expression and brain damage. RESULTS The available and present perspectives converge to show that rapamycin may disrupt the seizure circuitry initiated in the piriform cortex to mitigate seizure duration, severity, and brain damage. CONCLUSION The perspective provides a novel scenario to understand refractory epilepsy and selfsustaining status epilepticus. It is expected to provide a beneficial outcome in patients suffering from temporal lobe epilepsy.
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Affiliation(s)
| | - Roberta Celli
- I.R.C.C.S. Neuromed, Pozzilli, Italy;,Co-First Authors
| | - Filippo Sean Giorgi
- Human Anatomy, Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, Pisa, Italy
| | - Ferdinando Nicoletti
- I.R.C.C.S. Neuromed, Pozzilli, Italy;,Departments of Physiology and Pharmacology, University of Sapienza, Rome, Italy
| | - Francesco Fornai
- I.R.C.C.S. Neuromed, Pozzilli, Italy;,Human Anatomy, Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, Pisa, Italy;,Address correspondence to this author at I.R.C.C.S. Neuromed, via dell’elettronica, 86077 Pozzilli, Italy and Human Anatomy, Department of Translational Research and New Technologies in Medicine and Surgery, The University of Pisa, via Roma 55, 56126 Pisa, Italy; Tel: +39 0502218667; E-mails: ;
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Functional imaging of the piriform cortex in focal epilepsy. Exp Neurol 2020; 330:113305. [DOI: 10.1016/j.expneurol.2020.113305] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2019] [Revised: 01/26/2020] [Accepted: 04/08/2020] [Indexed: 11/19/2022]
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Giorgi FS, Galgani A, Gaglione A, Ferese R, Fornai F. Effects of Prolonged Seizures on Basal Forebrain Cholinergic Neurons: Evidence and Potential Clinical Relevance. Neurotox Res 2020; 38:249-265. [PMID: 32319018 DOI: 10.1007/s12640-020-00198-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2020] [Revised: 03/11/2020] [Accepted: 03/16/2020] [Indexed: 10/24/2022]
Abstract
Seizures originating from limbic structures, especially when prolonged for several minutes/hours up to status epilepticus (SE), can cause specific neurodegenerative phenomena in limbic and subcortical structures. The cholinergic nuclei belonging to the basal forebrain (BF) (namely, medial septal nucleus (MSN), diagonal band of Broca (DBB), and nucleus basalis of Meynert (NBM)) belong to the limbic system, while playing a pivotal role in cognition and sleep-waking cycle. Given the strong interconnections linking these limbic nuclei with limbic cortical structures, a persistent effect of SE originating from limbic structures on cBF morphology is plausible. Nonetheless, only a few experimental studies have addressed this issue. In this review, we describe available data and discuss their significance in the scenario of seizure-induced brain damage. In detail, the manuscript moves from a recent study in a model of focally induced limbic SE, in which the pure effects of seizure spreading through the natural anatomical pathways towards the cholinergic nuclei of BF were tracked by neuronal degeneration. In this experimental setting, a loss of cholinergic neurons was measured in all BF nuclei, to various extents depending on the specific nucleus. These findings are discussed in the light of the effects on the very same nuclei following SE induced by systemic injections of kainate or pilocarpine. The various effects including discrepancies among different studies are discussed. Potential implications for human diseases are included.
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Affiliation(s)
- Filippo Sean Giorgi
- Department of Translational Research and of New Surgical and Medical Technologies, University of Pisa, Pisa, Italy.
| | - Alessandro Galgani
- Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | | | | | - Francesco Fornai
- Department of Translational Research and of New Surgical and Medical Technologies, University of Pisa, Pisa, Italy.,IRCCS INM Neuromed, Pozzilli, Italy
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6
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Degeneration of cholinergic basal forebrain nuclei after focally evoked status epilepticus. Neurobiol Dis 2019; 121:76-94. [DOI: 10.1016/j.nbd.2018.09.019] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2018] [Revised: 09/12/2018] [Accepted: 09/18/2018] [Indexed: 12/14/2022] Open
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Myhrer T, Mariussen E, Aas P. Development of neuropathology following soman poisoning and medical countermeasures. Neurotoxicology 2018; 65:144-165. [DOI: 10.1016/j.neuro.2018.02.009] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2017] [Revised: 02/12/2018] [Accepted: 02/14/2018] [Indexed: 01/12/2023]
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Vismer MS, Forcelli PA, Skopin MD, Gale K, Koubeissi MZ. The piriform, perirhinal, and entorhinal cortex in seizure generation. Front Neural Circuits 2015; 9:27. [PMID: 26074779 PMCID: PMC4448038 DOI: 10.3389/fncir.2015.00027] [Citation(s) in RCA: 116] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2014] [Accepted: 05/15/2015] [Indexed: 12/11/2022] Open
Abstract
Understanding neural network behavior is essential to shed light on epileptogenesis and seizure propagation. The interconnectivity and plasticity of mammalian limbic and neocortical brain regions provide the substrate for the hypersynchrony and hyperexcitability associated with seizure activity. Recurrent unprovoked seizures are the hallmark of epilepsy, and limbic epilepsy is the most common type of medically-intractable focal epilepsy in adolescents and adults that necessitates surgical evaluation. In this review, we describe the role and relationships among the piriform (PIRC), perirhinal (PRC), and entorhinal cortex (ERC) in seizure-generation and epilepsy. The inherent function, anatomy, and histological composition of these cortical regions are discussed. In addition, the neurotransmitters, intrinsic and extrinsic connections, and the interaction of these regions are described. Furthermore, we provide evidence based on clinical research and animal models that suggest that these cortical regions may act as key seizure-trigger zones and, even, epileptogenesis.
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Affiliation(s)
- Marta S Vismer
- Department of Neurology, The George Washington University Washington, DC, USA
| | | | - Mark D Skopin
- Department of Neurology, The George Washington University Washington, DC, USA
| | - Karen Gale
- Department of Pharmacology, Georgetown University Washington, DC, USA
| | - Mohamad Z Koubeissi
- Department of Neurology, The George Washington University Washington, DC, USA
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Citraro R, Aiello R, Franco V, De Sarro G, Russo E. Targeting α-amino-3-hydroxyl-5-methyl-4-isoxazole-propionate receptors in epilepsy. Expert Opin Ther Targets 2014; 18:319-34. [PMID: 24387310 DOI: 10.1517/14728222.2014.874416] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
INTRODUCTION Despite epilepsies being between the oldest and most studied neurological diseases, new treatment remains an unmet need of scientific research due to the high percentage of refractory patients. Several studies have identified new suitable anti-seizure targets. Glutamate activation of α-amino-3-hydroxyl-5-methyl-4-isoxazole-propionate receptors (AMPARs) have long ago been identified as suitable targets for the development of anti seizure drugs. AREAS COVERED Here, we describe: i) AMPARs' structure and their involvement and role during seizures and in epilepsy and ii) the efficacy of AMPAR antagonists in preclinical models of seizures and epilepsy. EXPERT OPINION The physiological and pathological role of AMPAR in the CNS and the development of AMPAR antagonists have recently gained attention considering their recent involvement in status epilepticus and the marketing of perampanel. The need for new anti-seizure drugs represents a major challenge in both preclinical and clinical epilepsy. The introduction into the market of perampanel for the treatment of epilepsy will shed new light on the real potential of AMPAR antagonism in clinical settings outside the limited world of clinical trials. While research will go on in this area, fundamental will be the post-marketing evaluation of perampanel efficacy and tolerability and a better definition of the role of this receptor in the epileptic brain.
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Affiliation(s)
- Rita Citraro
- University "Magna Graecia" of Catanzaro, School of Medicine, Science of Health Department , Catanzaro , Italy
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Laufs H, Richardson MP, Salek-Haddadi A, Vollmar C, Duncan JS, Gale K, Lemieux L, Löscher W, Koepp MJ. Converging PET and fMRI evidence for a common area involved in human focal epilepsies. Neurology 2011; 77:904-10. [PMID: 21849655 DOI: 10.1212/wnl.0b013e31822c90f2] [Citation(s) in RCA: 84] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
OBJECTIVES Experiments in animal models have identified specific subcortical anatomic circuits, which are critically involved in the pathogenesis and control of seizure activity. However, whether such anatomic substrates also exist in human epilepsy is not known. METHODS We studied 2 separate groups of patients with focal epilepsies arising from any cortical location using either simultaneous EEG-fMRI (n = 19 patients) or [¹¹C]flumazenil PET (n = 18). RESULTS Time-locked with the interictal epileptiform discharges, we found significant hemodynamic increases common to all patients near the frontal piriform cortex ipsilateral to the presumed cortical focus. GABA(A) receptor binding in the same area was reduced in patients with more frequent seizures. CONCLUSIONS Our findings of cerebral blood flow and GABAergic changes, irrespective of where interictal or ictal activity occurs in the cortex, suggest that this area of the human primary olfactory cortex may be an attractive new target for epilepsy therapy, including neurosurgery, electrical stimulation, and focal drug delivery.
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Affiliation(s)
- H Laufs
- Department of Clinical and Experimental Epilepsy, Institute of Neurology, University College, London, UK.
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11
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Fornai F, Ruffoli R, Giorgi FS, Paparelli A. The role of locus coeruleus in the antiepileptic activity induced by vagus nerve stimulation. Eur J Neurosci 2011; 33:2169-78. [DOI: 10.1111/j.1460-9568.2011.07707.x] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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Kong S, Qian B, Liu J, Fan M, Chen G, Wang Y. Cyclothiazide induces seizure behavior in freely moving rats. Brain Res 2010; 1355:207-13. [PMID: 20678492 PMCID: PMC2947190 DOI: 10.1016/j.brainres.2010.07.088] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2010] [Revised: 07/22/2010] [Accepted: 07/24/2010] [Indexed: 01/27/2023]
Abstract
We have previously demonstrated that cyclothiazide (CTZ) is a potent convulsant drug inducing robust epileptiform activity in hippocampal neurons both in vitro and in vivo. Here we further establish an animal model for CTZ-induced behavioral seizures in freely moving rats. Microinjection of CTZ into the left ventricle dose-dependently induced robust seizure behaviors within 3h after administration. At a dose of 0.75 μmol, CTZ induced Racine score IV-V seizure behaviors in 71% (n=14) of the rats were tested. In addition, CTZ also induced epileptiform EEG activity accompanying behavioral seizures. The convulsant action of CTZ on both behavior and EEG was blocked by pretreatment with clinical anticonvulsant drug diazepam (n=5). In conclusion, our results demonstrate that CTZ is capable of inducing behavioral seizures in intact animals. Since CTZ acts on both GABAergic and glutamatergic systems, this new animal epilepsy model will be useful for anticonvulsant drug testing and general epilepsy research.
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Affiliation(s)
- Shuzhen Kong
- Research Centre of Medicinal Chemistry and Chemical Biology, Chongqing Technology and Business University, Chongqing, China
- Institutes of Brain Science and State Key Laboratory for Medical Neurobiology, Fudan University, Shanghai 200032, China
| | - Binbin Qian
- Institutes of Brain Science and State Key Laboratory for Medical Neurobiology, Fudan University, Shanghai 200032, China
| | - Jianhui Liu
- Research Centre of Medicinal Chemistry and Chemical Biology, Chongqing Technology and Business University, Chongqing, China
| | - Mingxin Fan
- Research Centre of Medicinal Chemistry and Chemical Biology, Chongqing Technology and Business University, Chongqing, China
| | - Gong Chen
- Department of Biology, Huck Institutes of Life Sciences, The Pennsylvania State University, University Park, PA 16802, USA
| | - Yun Wang
- Research Centre of Medicinal Chemistry and Chemical Biology, Chongqing Technology and Business University, Chongqing, China
- Institutes of Brain Science and State Key Laboratory for Medical Neurobiology, Fudan University, Shanghai 200032, China
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Modulators of metabotropic glutamate receptors microinfused into perirhinal cortex: Anticonvulsant effects in rats challenged with soman. Eur J Pharmacol 2010; 636:82-7. [DOI: 10.1016/j.ejphar.2010.02.047] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2009] [Revised: 02/11/2010] [Accepted: 02/24/2010] [Indexed: 11/23/2022]
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14
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Giorgi FS, Blandini F, Cantafora E, Biagioni F, Armentero MT, Pasquali L, Orzi F, Murri L, Paparelli A, Fornai F. Activation of brain metabolism and fos during limbic seizures: The role of Locus Coeruleus. Neurobiol Dis 2008; 30:388-399. [DOI: 10.1016/j.nbd.2008.02.008] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2007] [Revised: 02/12/2008] [Accepted: 02/22/2008] [Indexed: 11/16/2022] Open
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Addae JI, Ali N, Youssef FF, Stone TW. AMPA receptor activation reduces epileptiform activity in the rat neocortex. Brain Res 2007; 1158:151-7. [PMID: 17543292 DOI: 10.1016/j.brainres.2007.05.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2006] [Revised: 04/29/2007] [Accepted: 05/02/2007] [Indexed: 11/24/2022]
Abstract
We have previously reported that topical application of alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) to the rat neocortex prevents the effects of a subsequent application of N-methyl-d-aspartic acid (NMDA). Activation of NMDA receptors is involved in the pathogenesis of epileptic activity. Therefore, we examined if topically applied AMPA could affect changes in the somatosensory evoked potentials (SEPs) and electrocorticogram (ECoG) epileptic spikes caused by bicuculline. AMPA (50 microM) prevented the epileptiform activity to a level that was comparable to that caused by diazepam (3 mg/kg i.p.) or clomethiazole (100 mg/kg i.p.). Also, the epileptiform activity was suppressed by the AMPAR antagonist, CNQX, or the blocker of AMPAR desensitization, cyclothiazide. In the hippocampal slice, bicuculline-induced changes in the population spike potentials recorded from the CA1 cells were not affected by AMPA. We conclude that in the complex neuronal network of the rat neocortex, epileptiform activity can be suppressed in a variety of strategies that target the AMPA receptors: (1) blocking AMPA receptors, (2) promoting an apparent desensitization of AMPA receptors (possibly on the pyramidal neurons) or (3) reducing an apparent desensitization of AMPA receptors (possibly on the inhibitory GABA-ergic interneurons).
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Affiliation(s)
- Jonas I Addae
- Department of Preclinical Sciences, Faculty of Medical Sciences, University of the West Indies, St. Augustine Campus, Trinidad and Tobago.
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Pitkänen A, Mathiesen C, Rønn LCB, Møller A, Nissinen J. Effect of novel AMPA antagonist, NS1209, on status epilepticus. Epilepsy Res 2007; 74:45-54. [PMID: 17289347 DOI: 10.1016/j.eplepsyres.2006.12.004] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2006] [Revised: 12/19/2006] [Accepted: 12/22/2006] [Indexed: 10/23/2022]
Abstract
The current first line treatment of status epilepticus (SE) is based on the use of compounds that enhance GABAergic transmission or block sodium channels. These treatments discontinue SE in only two-thirds of patients, and therefore new therapeutic approaches are needed. We investigated whether a novel water-soluble AMPA antagonist, NS1209, discontinues SE in adult rats. SE was induced by electrical stimulation of the amygdala or subcutaneous administration of kainic acid. Animals were monitored continuously with video-electroencephalography during SE and drug treatment. We found that NS1209 could be safely administered to rats undergoing electrically induced SE at doses up to 50mg/kg followed by intravenous infusion of 5mg/kg for up to 24h. NS1209 administered as a bolus dose of 10-50mg/kg (i.p. or i.v.) followed by infusion of 4 or 5mg/kg h (i.v.) for 2-24h effectively discontinued electrically induced SE in all animals within 30-60 min, and there was no recurrence of SE after a 24-h infusion. Kainate-induced SE was similarly blocked by 10 or 30 mg/kg NS1209 (i.v.). To compare the efficacy and neuroprotective effects of NS1209 with those of diazepam (DZP), one group of rats received DZP (20mg/kg, i.p. and another dose of 10 mg/kg 6h later). By using the administration protocols described, the anticonvulsant effect of NS1209 was faster and more complete than that of DZP. NS1209 treatment (20 mg/kg bolus followed by 5mg/kg h infusion for 24 h) was neuroprotective against SE-induced hippocampal neurodegeneration, but to a lesser extent than DZP. These findings suggest that AMPA receptor blockade by NS1209 provides a novel and mechanistically complimentary addition to the armamentarium of drugs used to treat SE in humans.
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Affiliation(s)
- Asla Pitkänen
- A.I. Virtanen Institute, University of Kuopio, PO Box 1627, FIN-70 211 Kuopio, Finland.
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Lasztóczi B, Kardos J. Cyclothiazide Prolongs Low [Mg2+]–Induced Seizure-Like Events. J Neurophysiol 2006; 96:3538-44. [PMID: 16914619 DOI: 10.1152/jn.00287.2006] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Here we address the effects of cyclothiazide (CTZ), an allosteric inhibitor of α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA) receptor desensitization, on low [Mg2+]–induced seizure-like events (SLEs) recorded from the CA3 pyramidal layer of juvenile rat hippocampal slices. CTZ (100 μM) made the period of tonic-like discharges (161 ± 18% of control) and the whole SLE (151 ± 15% of control) longer (in 7 of 9 slices) or induced endless SLE by stabilizing clonic-like bursting (in 2 of 9 slices). CTZ (30 μM) had no significant effects on SLE dynamics ( n = 4), whereas 300 μM CTZ induced endless SLEs in four of eight slices. Coapplication of CTZ (100 μM) with 100 μM GYKI-52466, the allosteric inhibitor of AMPA receptor function, restrained the effects of CTZ and shortened SLEs and their tonic phases to 37 ± 4.2 and 47 ± 4.2% of the control, respectively. Effects of GYKI-52466 and GYKI-52466 with CTZ on SLE dynamics were indistinguishable. 4-aminopyridine (4-AP; 50 μM) alone ( n = 5) or in combination with CTZ ( n = 6) transformed recurrent SLE pattern into incessant epileptiform activity with patterns distinguishable from those under 100 μM CTZ application. The effect of 4-AP may suggest a role for facilitated presynaptic glutamate release in disrupting recurrent dynamics. In contrast, the self-similar slow-down of low [Mg2+]–induced SLE dynamics by CTZ indicate AMPA receptor desensitization as a parameter shaping SLEs.
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Affiliation(s)
- Bálint Lasztóczi
- Department of Neurochemistry, Institute of Biomolecular Chemistry, Chemical Research Center, Hungarian Academy of Sciences, Pusztaszeri út 59-67, Budapest H-1025, Hungary.
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Blandini F, Fancellu R, Armentero MT, Tassorelli C, Greco R, Fornai F, Nappi G. Unilateral lesion of the subthalamic nucleus enhances cortical fos expression associated with focally evoked seizures in the rat. Brain Res 2006; 1101:145-50. [PMID: 16782074 DOI: 10.1016/j.brainres.2006.05.025] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2006] [Revised: 05/05/2006] [Accepted: 05/07/2006] [Indexed: 10/24/2022]
Abstract
Reducing subthalamic nucleus (STN) activity has been proposed as an anti-epileptic procedure. Here we show that, on the contrary, a unilateral lesion of the STN causes slight (nonsignificant) increases in the severity of limbic seizures evoked by bicuculline infusion into the piriform cortex, associated with marked Fos expression throughout the cerebral cortex. Abolishing the STN control over the basal ganglia output may therefore play a facilitatory role on cortical activation associated with limbic seizures.
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Affiliation(s)
- Fabio Blandini
- Laboratory of Functional Neurochemistry, IRCCS Neurological Institute C. Mondino, Via Mondino, 2, 27100 Pavia, Italy.
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Qi J, Wang Y, Jiang M, Warren P, Chen G. Cyclothiazide induces robust epileptiform activity in rat hippocampal neurons both in vitro and in vivo. J Physiol 2006; 571:605-18. [PMID: 16423850 PMCID: PMC1805799 DOI: 10.1113/jphysiol.2005.103812] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
Cyclothiazide (CTZ) is a potent blocker of AMPA receptor desensitization. We have recently demonstrated that CTZ also inhibits GABA(A) receptors. Here we report that CTZ induces robust epileptiform activity in hippocampal neurons both in vitro and in vivo. We first found that chronic treatment of hippocampal cultures with CTZ (5 microM, 48 h) results in epileptiform activity in the majority of neurons (80%). The epileptiform activity lasts more than 48 h after washing off CTZ, suggesting a permanent change of the neural network properties after CTZ treatment. We then demonstrated in in vivo recordings that injection of CTZ (5 micromol in 5 microl) into the lateral ventricles of anaesthetized rats also induces spontaneous epileptiform activity in the hippocampal CA1 region. The epileptogenic effect of CTZ is probably due to its enhancing glutamatergic neurotransmission as shown by increasing the frequency and decay time of mEPSCs, and simultaneously inhibiting GABAergic neurotransmission by reducing the frequency of mIPSCs. Comparing to a well-known epileptogenic agent kainic acid (KA), CTZ affects neuronal activity mainly through modulating synaptic transmission without significant change of the intrinsic membrane excitability. Unlike KA, which induces significant cell death in hippocampal cultures, CTZ treatment does not result in any apparent neuronal death. Therefore, the CTZ-induced epilepsy model may provide a novel research tool to elucidate the molecular and cellular mechanisms of epileptogenesis without any complication from drug-induced cell death. The long-lasting epileptiform activity after CTZ washout may also make it a very useful model in screening antiepileptic drugs.
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Affiliation(s)
- Jinshun Qi
- Department of Biology, 201 Life Sciences Building, The Pennsylvania State University, University Park, PA 16802, USA
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